first series - 2 4 - 8 10 here missing no is 6

second series 2 6 10 14 here missing no is 18 strong text

The answer is 6 It follows the logic 2 , 2, 2+2, 4+2, 4 + 2

In series 6,4,1,2,2,8,7,4,2,1,5,3,8,6,2,1,7,1,4,1,3,2,8,7,6, how many pairs of successive numbers have a difference of 1 each?

On behalf of Sture Sjöstedt